Secondary-anti-(mouse immunoglobulin) antibodies have long been used to detect the binding of monoclonal antibodies (MAbs) to the target antigens. This is advantageous because it combines the exquisite specificity found in primary MAb with the amplification and versatility allowed by the second antibody reagent. Using specific anti-immunoglobulin antibodies solves many of the difficulties in locating and quantitating antibodies when these molecules are found in complex mixtures of serum or tissue culture proteins.
A concern in the generation of anti-immunoglobulin response is how similar antibodies are from species to species. Because of this extraordinary similarity between the amino add sequence of different species immunoglobulin (Ig), it has been difficult to obtain a secondary, anti-(mouse)Ig antibody preparation which does not also bind to the Ig of other species.
The cross-reactive binding found in anti-immunoglobulin antibodies may create false negative or positive assay results. Thus, experiments performed in serum or other biological fluids have required washing steps or other techniques to remove potentially cross-reactive antibodies before employing the second antibody. Because of the high concentrations present in vivo, this problem of cross reactivity has prevented effective use of a second antibody system for studying primary mouse monoclonal antibodies in animals.
Anti-Ig antibodies are employed in the various number of assays. Accordingly, there is a need for high affinity monoclonal antibodies which are species specific.